The present invention relates to an improved fluid valve structure, more particularly one which combines anti-siphon and anti-backflow features in a single element.
The valve structure of the present invention is in the category or class of valves which are adapted to insertion in a fluid feed line between a nozzle or discharge orifice and the fluid supply from which fluid is drawn. Such a valve can be used in a multiplicity of lines and is especially adaptable to self-contained fluid systems or in systems having limited space.
The invention is herein described in the context of the utilization of water systems which are found in mobile homes or recreational vehicles, and is applicable to any system which incorporates a flexible hose connection, whether it be found in a shower, wash basin, bath tub, or the like. The valve of this structure is especially useful in such an environment due to the fact that such fluid systems incorporate a closed or self-contained water supply source from which all utilization of water derives. Another characteristic of such systems is that they operate under low fluid pressure conditions.
Because of the character of such a self-contained water supply system and the danger of contaminating the water, such systems are subject to rather stringent sanitary codes which require the insertion in the supply line of valves which prevent back flow or re-entry into the system of previously used or contaminated water.
Valves designed to achieve this result have been in use for several years, and are associated with or contain means to permit the entry of air into the water line under conditions that would otherwise create a siphon condition. In such valves, many complex designs have been used in order to open and close such air vents and to prevent the fluid from leaking through said air vents.
Most existing valves incorporate dual co-operating air valves and check valves, some of which are cumbersome and large, but all of which are relatively expensive. Even those incorporating a single valve chamber, such as in U.S. Pat. No. 3,951,164, utilize very complex structure within that chamber.
It is accordingly an object of this invention to provide a novel valve structure which is simple in its design, efficient in its operation and which is inexpensive to produce.